SC 13D

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 13D

Under the Securities Exchange Act of 1934*

WuXi PharmaTech (Cayman) Inc.

(Name of Issuer)

Ordinary Shares, Par Value $0.02 Per Share

(Title of Class of Securities)

929352102

(CUSIP Number)

Scott A. Arenare, Esq.

Managing Director and General Counsel

Warburg Pincus LLC

466 Lexington Avenue

New York, NY  10017

(212) 878-0600

(Name, Address and Telephone Number of Person

Authorized to Receive Notices and Communications)

With a copy to:

Steven J. Gartner, Esq.

Willkie Farr & Gallagher LLP

787 Seventh Avenue

New York, NY 10019

(212) 728-8000

July 2, 2008

(Date of Event which Requires Filing of This Statement)

If the filing person has previously filed a statement on Schedule 13G to report the acquisition that is the subject of this Schedule 13D, and is filing this schedule because of §§ 240.13d-1(e), 240.13d-1(f) or 240.13d-1(g), check the following box: o

NOTE: Schedules filed in paper format shall include a signed original and five copies of the schedule, including all exhibits.  See Rule 240.13d-7 for other parties to whom copies are to be sent.

* The remainder of this cover page shall be filled out for a reporting person’s initial filing on this form with respect to the subject class of securities, and for any subsequent amendment containing information which would alter disclosures provided in a prior cover page.

The information required on the remainder of this cover page shall not be deemed to be “filed” for the purpose of Section 18 of the Securities Exchange Act of 1934 (“Act”) or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes).

2

				SCHEDULE 13D
CUSIP No. – 929352102					Page 3 of 19 pages
1	NAME OF REPORTING PERSONS I.R.S. IDENTIFICATION NOS. OF  ABOVE PERSONS (ENTITIES ONLY) Warburg Pincus Private Equity X, L.P. 26-0849130
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (a)    o (b)   x
3	SEC USE ONLY
4	SOURCE OF FUNDS WC
5	CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEM 2(d) OR 2(e) o
6	CITIZENSHIP OR PLACE OF ORGANIZATION Delaware
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH		7	SOLE VOTING POWER -0-
		8	SHARED VOTING POWER 25,977,440
		9	SOLE DISPOSITIVE POWER -0-
		10	SHARED DISPOSITIVE POWER 25,977,440
11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 25,977,440
12	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES (See Instructions) o
13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 5.2%
14	TYPE OF REPORTING PERSON PN

3

				SCHEDULE 13D
CUSIP No. – 929352102					Page 4 of 19 pages
1	NAME OF REPORTING PERSONS I.R.S. IDENTIFICATION NOS. OF  ABOVE PERSONS (ENTITIES ONLY) Warburg Pincus X Partners, L.P. 77-0698056
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (a)    o (b)   x
3	SEC USE ONLY
4	SOURCE OF FUNDS WC
5	CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEM 2(d) OR 2(e) o
6	CITIZENSHIP OR PLACE OF ORGANIZATION Delaware
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH		7	SOLE VOTING POWER -0-
		8	SHARED VOTING POWER 831,056
		9	SOLE DISPOSITIVE POWER -0-
		10	SHARED DISPOSITIVE POWER 831,056
11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 831,056
12	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES (See Instructions) o
13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 0.2%
14	TYPE OF REPORTING PERSON PN

4

				SCHEDULE 13D
CUSIP No. -  929352102					Page 5 of 19 pages
1	NAME OF REPORTING PERSONS I.R.S. IDENTIFICATION NOS. OF  ABOVE PERSONS (ENTITIES ONLY) Warburg Pincus X, L.P. 26-0403670
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (a)    o (b)   x
3	SEC USE ONLY
4	SOURCE OF FUNDS N/A
5	CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEM 2(d) OR 2(e) o
6	CITIZENSHIP OR PLACE OF ORGANIZATION Delaware
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH		7	SOLE VOTING POWER -0-
		8	SHARED VOTING POWER 26,808,496
		9	SOLE DISPOSITIVE POWER -0-
		10	SHARED DISPOSITIVE POWER 26,808,496
11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 26,808,496
12	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES (See Instructions) o
13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 5.4%
14	TYPE OF REPORTING PERSON PN

5

				SCHEDULE 13D
CUSIP No. -  929352102					Page 6 of 19 pages
1	NAME OF REPORTING PERSONS I.R.S. IDENTIFICATION NOS. OF  ABOVE PERSONS (ENTITIES ONLY) Warburg Pincus X LLC 26-0403605
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (a)    o (b)   x
3	SEC USE ONLY
4	SOURCE OF FUNDS N/A
5	CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEM 2(d)OR 2(e) o
6	CITIZENSHIP OR PLACE OF ORGANIZATION New York
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH		7	SOLE VOTING POWER -0-
		8	SHARED VOTING POWER 26,808,496
		9	SOLE DISPOSITIVE POWER -0-
		10	SHARED DISPOSITIVE POWER 26,808,496
11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 26,808,496
12	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES (See Instructions) o
13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 5.4%
14	TYPE OF REPORTING PERSON OO

6

				SCHEDULE 13D
CUSIP No. -  929352102					Page 7 of 19 pages
1	NAME OF REPORTING PERSONS I.R.S. IDENTIFICATION NOS. OF  ABOVE PERSONS (ENTITIES ONLY) Warburg Pincus Partners, LLC 13-4069737
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (a)    o (b)   x
3	SEC USE ONLY
4	SOURCE OF FUNDS N/A
5	CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEM 2(d) OR 2(e) o
6	CITIZENSHIP OR PLACE OF ORGANIZATION New York
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH		7	SOLE VOTING POWER -0-
		8	SHARED VOTING POWER 26,808,496
		9	SOLE DISPOSITIVE POWER -0-
		10	SHARED DISPOSITIVE POWER 26,808,496
11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 26,808,496
12	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES (See Instructions) o
13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 5.4%
14	TYPE OF REPORTING PERSON OO

7

				SCHEDULE 13D
CUSIP No. -  929352102					Page 8 of 19 pages
1	NAME OF REPORTING PERSONS I.R.S. IDENTIFICATION NOS. OF  ABOVE PERSONS (ENTITIES ONLY) Warburg Pincus LLC 13-3536050
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (a)    o (b)   x
3	SEC USE ONLY
4	SOURCE OF FUNDS N/A
5	CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEM 2(d) OR 2(e) o
6	CITIZENSHIP OR PLACE OF ORGANIZATION New York
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH		7	SOLE VOTING POWER -0-
		8	SHARED VOTING POWER 26,808,496
		9	SOLE DISPOSITIVE POWER -0-
		10	SHARED DISPOSITIVE POWER 26,808,496
11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 26,808,496
12	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES (See Instructions) o
13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 5.4%
14	TYPE OF REPORTING PERSON OO

8

				SCHEDULE 13D
CUSIP No. -  929352102					Page 9 of 19 pages
1	NAME OF REPORTING PERSONS I.R.S. IDENTIFICATION NOS. OF  ABOVE PERSONS (ENTITIES ONLY) Warburg Pincus & Co. 13-6358475
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (a)    o (b)   x
3	SEC USE ONLY
4	SOURCE OF FUNDS N/A
5	CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEM 2(d) OR 2(e) o
6	CITIZENSHIP OR PLACE OF ORGANIZATION New York
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH		7	SOLE VOTING POWER -0-
		8	SHARED VOTING POWER 26,808,496
		9	SOLE DISPOSITIVE POWER -0-
		10	SHARED DISPOSITIVE POWER 26,808,496
11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 26,808,496
12	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES (See Instructions) o
13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 5.4%
14	TYPE OF REPORTING PERSON PN

9

				SCHEDULE 13D
CUSIP No. -  929352102					Page 10 of 19 pages
1	NAME OF REPORTING PERSONS I.R.S. IDENTIFICATION NOS. OF  ABOVE PERSONS (ENTITIES ONLY) Charles R. Kaye
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (a)    o (b)   x
3	SEC USE ONLY
4	SOURCE OF FUNDS N/A
5	CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEM 2(d) OR 2(e) o
6	CITIZENSHIP OR PLACE OF ORGANIZATION United States of America
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH		7	SOLE VOTING POWER -0-
		8	SHARED VOTING POWER 26,808,496
		9	SOLE DISPOSITIVE POWER -0-
		10	SHARED DISPOSITIVE POWER 26,808,496
11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 26,808,496
12	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES (See Instructions) o
13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 5.4%
14	TYPE OF REPORTING PERSON IN

10

				SCHEDULE 13D
CUSIP No. -  929352102					Page 11 of 19 pages
1	NAME OF REPORTING PERSONS I.R.S. IDENTIFICATION NOS. OF  ABOVE PERSONS (ENTITIES ONLY) Joseph P. Landy
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (a)    o (b)   x
3	SEC USE ONLY
4	SOURCE OF FUNDS N/A
5	CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEM 2(d) OR 2(e) o
6	CITIZENSHIP OR PLACE OF ORGANIZATION United States of America
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH		7	SOLE VOTING POWER -0-
		8	SHARED VOTING POWER 26,808,496
		9	SOLE DISPOSITIVE POWER -0-
		10	SHARED DISPOSITIVE POWER 26,808,496
11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 26,808,496
12	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES (See Instructions) o
13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 5.4%
14	TYPE OF REPORTING PERSON IN

11

Item 1.    Security and Issuer

This statement on Schedule 13D (the “Schedule 13D”) relates to the ordinary shares, par value $0.02 per share (the “Ordinary Shares”), of WuXi PharmaTech (Cayman) Inc., a Cayman Islands corporation (the “Company”), and is being filed pursuant to Rule 13d-1 promulgated under the Securities Exchange Act of 1934, as amended (the “Exchange Act”).  The principal executive offices of the Company are located 288 Fute Zhong Road, Waigaoqiao Free Trade Zone, Shanghai 200131, People’s Republic of China.

Item 2.    Identity and Background

(a)  This Schedule 13D is being filed by Warburg Pincus Private Equity X, L.P., a Delaware limited partnership (“WP X”), Warburg Pincus X Partners, L.P., a Delaware limited partnership (“WPP X” and together with WP X, the “Funds”), Warburg Pincus X, L.P., a Delaware limited partnership and the sole general partner of each of the Funds (“WP X LP”), Warburg Pincus X LLC (“WP X LLC”), a New York limited liability company and the sole general partner of WP X LP, Warburg Pincus Partners LLC (“WPP LLC”), a New York limited liability company and the sole member of WP X LLC, Warburg Pincus LLC, a New York limited liability company that manages each of the Funds (“WP LLC”), Warburg Pincus & Co. (“WP”), a New York general partnership and the managing member of WPP LLC, and Messrs. Charles R. Kaye and Joseph P. Landy, each a Managing General Partner of WP and Co-President and Managing Member of WP LLC (Mr. Kaye, Mr. Landy, WP X, WPP X, WP X LP, WP X LLC, WPP LLC, WP LLC and WP collectively being referred to as the “Reporting Persons”).  The agreement among the Reporting Persons to file this Schedule 13D jointly in accordance with Rule 13d-1(k) of the Exchange Act is attached hereto as Exhibit 1.

(b)   The address of the principal business and principal office of each of the Reporting Persons is c/o Warburg Pincus LLC, 466 Lexington Avenue, New York, New York 10017.  The general partners of WP and the members of WP LLC, and their respective business addresses, are set forth on Schedule I hereto.

(c)    The principal business of the Funds is that of making private equity and related investments.  The principal business of WP is acting as the managing member of WPP LLC.  The principal business of WPP LLC is acting as general partner to certain private equity funds and as the sole member of WP X LLC.  The principal business of WP X LLC is acting as general partner of WP X LP.  The principal business of WP X LP is acting as general partner of the Funds.  The principal business of WP LLC is managing certain private equity funds, including the Funds.  The principal business of each Mr. Kaye and Mr. Landy is acting as a Managing General Partner of WP and Co-President and Managing Member of WP LLC.  The principal occupation of each of the general partners of WP and the members of WP LLC is set forth on Schedule I hereto.

(d)   During the last five years, none of the Reporting Persons and, to the knowledge of the Reporting Persons, none of the general partners, members or directors named on Schedule I, has been convicted in a criminal proceeding (excluding traffic violations or similar misdemeanors).

12

(e)    During the last five years, none of the Reporting Persons and, to the knowledge of the Reporting Persons, none of the general partners, members or directors named on Schedule I, has been a party to a civil proceeding of a judicial or administrative body of competent jurisdiction and as a result of such proceeding was or is subject to a judgment, decree, or final order enjoining future violations of, or prohibiting or mandating activity subject to, federal or state securities laws or finding any violations with respect to such laws.

(f)    WP X, WPP X and WP X LP are each limited partnerships organized under the laws of the State of Delaware.  WP X LLC, WPP LLC and WP LLC are each limited liability companies organized under the laws of the State of New York.  WP is a general partnership organized under the laws of the State of New York.  Messrs. Kaye and Landy are citizens of the United States of America.  Except as otherwise indicated on Schedule I hereto, each of the individuals referred to on Schedule I hereto is a citizen of the United States of America.

Item 3.    Source and Amount of Funds or Other Consideration

On June 1, 2008, the Funds entered into a Share Purchase Agreement (the “Share Purchase Agreement”), as amended by Amendment No. 1 to the Share Purchase Agreement, dated July 2, 2008 (the “Amendment” and together with the Share Purchase Agreement, the “Purchase Agreement”), with UOB Hermes Asia Technology Fund, a Cayman Islands exempted company, UOB JAIC Venture Bio Investments Limited, a Singaporean limited liability company, and UOB Venture Technology Investments Ltd., a Singaporean limited liability company (together, the “Selling Shareholders”). Pursuant to the Purchase Agreement, the Funds agreed to purchase Ordinary Shares from the Selling Shareholders.  At the closing of the transaction on July 2, 2008 (the “Closing Date”), the Selling Shareholders sold a total of 26,808,496 Ordinary Shares to the Funds for an aggregate purchase price of $62,999,965.60, or $2.35 per share.  Copies of the Share Purchase Agreement and the Amendment are attached hereto as Exhibits 2 and 3, respectively, and are incorporated herein by reference.

All of the funds required to acquire the Ordinary Shares were obtained from the working capital of each of the Funds, which in turn was obtained from capital contributions from the respective limited partners of the Funds.

Item 4.    Purpose of Transaction

The acquisition by the Funds of the Ordinary Shares as described herein was effected because of the belief that the Ordinary Shares represent an attractive investment.  The Funds beneficially own, and the Reporting Persons may be deemed to beneficially own, the Ordinary Shares as an investment.  Depending on prevailing market, economic and other conditions, the Reporting Persons may from time to time acquire additional Ordinary Shares or engage in discussions with the Company concerning future acquisitions of shares of its capital stock.  Such acquisitions may be made by means of open-market purchases, privately negotiated transactions, direct acquisitions from the Company or otherwise.  The Reporting Persons intend to review their investment in the Company on a continuing basis and, depending upon the price

13

and availability of shares of the Company’s capital stock, subsequent developments affecting the Company, the Company’s business and prospects, other investment and business opportunities available to the Reporting Persons, general stock market and economic conditions, tax considerations and other factors considered relevant, may decide at any time to increase or to decrease the size of their investment in the Company.

Terms of the Purchase Agreement

Pursuant to the Purchase Agreement, the Funds agreed to purchase, and the Selling Shareholders agreed to sell to the Funds, a total of 26,808,496 Ordinary Shares for an aggregate price of $62,999,965.60.  WP X purchased 25,977,440 Ordinary Shares and WPP X purchased 831,056 Ordinary Shares of such total.

Pursuant to Section 4(e) of the Share Purchase Agreement, the Selling Shareholders agreed to consult with and recommend to the Company that the Funds be permitted to have board observer rights on terms and conditions to be agreed upon between the Funds and the Company. The Reporting Persons expect to engage in discussions with the Company concerning possible representation on the Company’s Board of Directors (the “Board”) or observer rights.

Terms of the Registration Rights Agreement

In connection with the closing of the transactions contemplated by the Purchase Agreement, the Funds, the Selling Shareholders and the Company executed an Assignment Agreement (the “Assignment Agreement”) (included as Exhibit C to the Share Purchase Agreement), pursuant to which the Selling Shareholders assigned, transferred and conveyed all rights and obligations under that certain Registration Rights Agreement, dated June 4, 2007, by and among the Company, WuXi PharmaTech (BVI) Inc. and the persons listed on Schedule I thereto (incorporated by reference to Exhibit 4.7 to the Company’s Registration Statement on Form F-1 (Registration No. 333-144806), filed with the U.S. Securities and Exchange Commission on July 24, 2007) (the “Registration Rights Agreement”).

Pursuant to the Registration Rights Agreement, the Funds have been granted certain demand and piggy-back registrations rights with respect to the Ordinary Shares.

Additional Disclosure

Except as set forth above in this statement, none of the Reporting Persons nor, to the best of their knowledge, any of the persons set forth on Schedule I or listed in Item 2(e) hereto, has any plans or proposals that relate to or would result in: (a) the acquisition by any person of additional securities of the Company, or the disposition of securities of the Company; (b) an extraordinary corporate transaction, such as a merger, reorganization or liquidation, involving the Company or any of its subsidiaries; (c) a sale or transfer of a material amount of assets of the Company or any of its subsidiaries; (d) any change in the present Board or management of the Company, including any plans or proposals to change the number or term of directors or to fill any existing vacancies on the Board; (e) any material change in the present capitalization or dividend policy of the Company; (f) any other material change in the

14

Company’s business or corporate structure; (g) changes in the Company’s charter, by-laws or instruments corresponding thereto or other actions which may impede the acquisition of control of the Company by any person; (h) causing a class of securities of the Company to be delisted from a national securities exchange or to cease to be authorized to be quoted in an inter-dealer quotation system of a registered national securities association; (i) a class of equity securities of the Company becoming eligible for termination of registration pursuant to Section 12(g)(4) of the Exchange Act; or (j) any action similar to any of those enumerated above.

Item 5.    Interest in Securities of the Issuer

(a)           The percentages used herein are calculated based upon the 499,600,302 Ordinary Shares that were outstanding as of March 31, 2008 as reported in the Company’s Form 6-K filed with the Securities and Exchange Commission on May 27, 2008.

WP X is the direct owner of 25,977,440 Ordinary Shares, representing approximately 5.2% of the outstanding Ordinary Shares. WPP X is the direct owner of 831,056 Ordinary Shares, representing approximately 0.2% of the outstanding Ordinary Shares.  Accordingly, as of July 2, 2008, the Funds may be deemed to beneficially own an aggregate of 26,808,496 Ordinary Shares, representing approximately 5.4% of the outstanding Ordinary Shares.

Due to their respective relationships with the Funds and each other, each of the Reporting Persons may be deemed to beneficially own, in the aggregate, 26,808,496 Ordinary Shares.  Each of WP, WPP LLC, WP LLC, WP X LLC, WP X LP, Mr. Kaye and Mr. Landy disclaim beneficial ownership (within the meaning of Rule 13d-3 under the Exchange Act) of all of the Ordinary Shares.

(b)           Each of the Reporting Persons is deemed to share with the Funds the power to vote or to direct the vote and to dispose or to direct the disposition of 26,808,496 Ordinary Shares.

(c)           Except for the transactions described in Items 3 and 4 above, no other transactions in the Ordinary Shares were effected by the Reporting Persons or any persons set forth on Schedule I hereto during the sixty days before the date of this Schedule 13D.

(d)           Except as set forth in this Item 5, no person other than each respective record owner referred to herein of the Ordinary Shares is known to have the right to receive or the power to direct the receipt of dividends from, or the proceeds from the sale of, such securities.

(e)           Not applicable.

15

Item 6.    Contracts, Arrangements, Understandings or Relationships with Respect to Securities of the Company

Pursuant to Rule 13d-1(k) promulgated under the Exchange Act, the Reporting Persons have entered into an agreement, attached hereto as Exhibit 1, with respect to the joint filing of this Schedule 13D and any amendment or amendments hereto.

The Purchase Agreement is described in Item 3 and Item 4 above, such summary being incorporated in this Item 6 by reference.  The summary of the Purchase Agreement in this Schedule 13D is qualified in its entirety by reference to the Share Purchase Agreement, a copy of which is attached hereto as Exhibit 2, and the Amendment, a copy of which is attached hereto as Exhibit 3.

The Registration Rights Agreement is described in Item 4 above, such summary being incorporated in this Item 6 by reference.  The summary of Registration Rights Agreement in this Schedule 13D is qualified in its entirety by reference to the Registration Rights Agreement, a copy of which is attached as Exhibit 4.7 to the Company’s Registration Statement on Form F-1 (Registration No. 333-144806), filed with the U.S. Securities and Exchange Commission on July 24, 2007.

The Assignment Agreement is described in Item 4 above, such summary being incorporated in this Item 6 by reference.  The summary of the Assignment Agreement in this Schedule 13D is qualified in its entirety by reference to the Assignment Agreement, a copy of which is attached hereto as Exhibit C to the Share Purchase Agreement.

Except as described herein, there are no contracts, arrangements, understandings or relationships (legal or otherwise) among the persons named in Item 2 above or between such persons and any other person with respect to any securities of the Company.

Item 7.    Material to Be Filed as Exhibits

Exhibit 1	Joint Filing Agreement, dated July 14, 2008, among the Reporting Persons, relating to the filing of a joint statement on Schedule 13D.
Exhibit 2	Share Purchase Agreement, dated June 1, 2008, by and among the Selling Shareholders listed on Schedule 1 thereto and Warburg Pincus Private Equity X, L.P. and Warburg Pincus X Partners L.P.
Exhibit 3	Amendment No. 1 to the Share Purchase Agreement, dated July 2, 2008, by and among UOB Hermes Asia Technology Fund, UOB JAIC Venture Bio Investments Limited, UOB Venture Technology Investments Ltd. and Warburg Pincus Private Equity X, L.P. and Warburg Pincus X Partners L.P.
Exhibit 4	Assignment Agreement, dated July 2, 2008, by and among UOB Hermes Asia Technology Fund, UOB JAIC Venture Bio Investments Limited, UOB Venture Technology Investments Ltd. and Warburg Pincus Private Equity X, L.P. and Warburg Pincus X Partners L.P. (included as Exhibit C to the Share Purchase Agreement, a copy of which is attached hereto as Exhibit 2).

16

Exhibit 5 Registration Rights Agreement, dated June 4, 2007, by and among the Company, WuXi PharmaTech (BVI) Inc. and the persons listed on Schedule I thereto (incorporated by reference to Exhibit 4.7 to the Company’s Registration Statement on Form F-1 (Registration No. 333-144806), filed with the U.S. Securities and Exchange Commission on July 24, 2007).

17

SIGNATURES

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

Dated: July 14, 2008

WARBURG PINCUS PRIVATE EQUITY X, L.P.
By: Warburg Pincus X, L.P., its general partner
By: Warburg Pincus X LLC, its general partner
By: Warburg Pincus Partners, LLC, its managing member
By: Warburg Pincus & Co., its managing
member
By:		/s/ Scott A. Arenare
		Name: Scott A. Arenare
		Title: Partner
WARBURG PINCUS X PARTNERS, L.P.
By: Warburg Pincus X, L.P., its general partner
By: Warburg Pincus X LLC, its general partner
By: Warburg Pincus Partners, LLC, its managing member
By: Warburg Pincus & Co., its managing
member
By:		/s/ Scott A. Arenare
		Name: Scott A. Arenare
		Title: Partner
WARBURG PINCUS X, L.P.
By: Warburg Pincus X LLC, its general partner
By: Warburg Pincus Partners, LLC, its managing member
By: Warburg Pincus & Co., its managing member
By:	/s/ Scott A. Arenare
	Name: Scott A. Arenare
	Title: Partner
WARBURG PINCUS X LLC
By: Warburg Pincus Partners, LLC, its sole
member
By: Warburg Pincus & Co., its managing
member
By:		/s/ Scott A. Arenare
		Name: Scott A. Arenare
		Title: Partner

WARBURG PINCUS PARTNERS, LLC
By: Warburg Pincus & Co., its managing
member
By:	/s/ Scott A. Arenare
	Name: Scott A. Arenare
	Title: Partner
WARBURG PINCUS & CO.
By:	/s/ Scott A. Arenare
	Name: Scott A. Arenare
	Title: Partner
By:	/s/ Scott A. Arenare
	Name: Charles R. Kaye
	By: Scott A. Arenare, Attorney-in-Fact*
By:	/s/ Scott A. Arenare
	Name: Joseph P. Landy
	By: Scott A. Arenare, Attorney-in-Fact**

*  Power of Attorney given by Mr. Kaye was previously filed with the Securities and Exchange Commission on March 2, 2006 as an exhibit to a Schedule 13D filed by Building Products, LLC with respect to Builders FirstSource, Inc.

**  Power of Attorney given by Mr. Landy was previously filed with the Securities and Exchange Commission on March 2, 2006 as an exhibit to a Schedule 13D filed by Building Products, LLC with respect to Builders FirstSource, Inc.

EX-1

EXHIBIT 1

JOINT FILING AGREEMENT

THIS JOINT FILING AGREEMENT is entered into as of July 14, 2008, by and among the parties hereto.  The undersigned hereby agree that the Statement on Schedule 13D with respect to the ordinary shares, par value $0.02 per share, of WuXi PharmaTech (Cayman) Inc. and any amendment thereafter signed by each of the undersigned shall be, filed on behalf of each undersigned pursuant to and in accordance with the provisions of 13d-1(k) under the Securities Exchange Act of 1934, as amended.

WARBURG PINCUS PRIVATE EQUITY X, L.P.
By: Warburg Pincus X, L.P., its general partner
By: Warburg Pincus X LLC, its general partner
By: Warburg Pincus Partners, LLC, its managing member
By: Warburg Pincus & Co., its managing
member
By:	/s/ Scott A. Arenare
	Name: Scott A. Arenare
	Title: Partner
WARBURG PINCUS X PARTNERS, L.P.
By: Warburg Pincus X, L.P., its general partner
By: Warburg Pincus X LLC, its general partner
By: Warburg Pincus Partners, LLC, its managing member
By: Warburg Pincus & Co., its managing
member
By:	/s/ Scott A. Arenare
	Name: Scott A. Arenare
	Title: Partner
WARBURG PINCUS X, LLC
By: Warburg Pincus Partners, LLC, its sole
member
By: Warburg Pincus & Co., its managing
member
By:	/s/ Scott A. Arenare
	Name: Scott A. Arenare
	Title: Partner
WARBURG PINCUS X, L.P.
By: Warburg Pincus X LLC, its general partner
By: Warburg Pincus Partners, LLC, its managing member
By: Warburg Pincus & Co., its managing
member
By:	/s/ Scott A. Arenare
	Name: Scott A. Arenare
	Title: Partner

WARBURG PINCUS PARTNERS, LLC
By: Warburg Pincus & Co., its managing
member
By:	/s/ Scott A. Arenare
	Name: Scott A. Arenare
	Title: Partner
WARBURG PINCUS & CO.
By:	/s/ Scott A. Arenare
	Name: Scott A. Arenare
	Title: Partner
By:	/s/ Scott A. Arenare
	Name: Charles R. Kaye
	By: Scott A. Arenare, Attorney-in-Fact
By:	/s/ Scott A. Arenare
	Name: Joseph P. Landy
	By: Scott A. Arenare, Attorney-in-Fact

SCHEDULE I

Set forth below is the name, position and present principal occupation of each of the general partners of Warburg Pincus & Co. (“WP”) and members of Warburg Pincus LLC (including its subsidiaries, “WP LLC”).  Except as otherwise indicated, the business address of each of such persons is 466 Lexington Avenue, New York, New York 10017, and each of such persons is a citizen of the United States.

GENERAL PARTNERS OF WP

NAME	PRESENT PRINCIPAL OCCUPATION IN ADDITION TO POSITION WITH WP, AND POSITIONS WITH THE REPORTING ENTITIES
Joel Ackerman	Partner of WP; Member and Managing Director of WP LLC
Scott A. Arenare	Partner of WP; Member and Managing Director of WP LLC
David Barr	Partner of WP; Member and Managing Director of WP LLC
Sean D. Carney	Partner of WP; Member and Managing Director of WP LLC
Mark Colodny	Partner of WP; Member and Managing Director of WP LLC
David A. Coulter	Partner of WP; Member and Managing Director of WP LLC
Timothy J. Curt	Partner of WP; Member and Managing Director of WP LLC
W. Bowman Cutter	Partner of WP; Member and Managing Director of WP LLC
Cary J. Davis	Partner of WP; Member and Managing Director of WP LLC
Steven Glenn	Partner of WP; Member and Managing Director of WP LLC
Michael Graff	Partner of WP; Member and Managing Director of WP LLC
Patrick T. Hackett	Partner of WP; Member and Managing Director of WP LLC
E. Davisson Hardman	Partner of WP; Member and Managing Director of WP LLC
Jeffrey A. Harris	Partner of WP; Member and Managing Director of WP LLC
Stewart J. Hen	Partner of WP; Member and Managing Director of WP LLC
William H. Janeway	Partner of WP; Member and Senior Advisor of WP LLC
Chansoo Joung	Partner of WP; Member and Managing Director of WP LLC
Peter R. Kagan	Partner of WP; Member and Managing Director of WP LLC
Charles R. Kaye	Managing General Partner of WP; Managing Member and Co-President of WP LLC
Henry Kressel	Partner of WP; Member and Managing Director of WP LLC
David Krieger	Partner of WP; Member and Managing Director of WP LLC
Kevin Kruse	Partner of WP; Member and Managing Director of WP LLC
Joseph P. Landy	Managing General Partner of WP; Managing Member and Co-President of WP LLC
Kewsong Lee	Partner of WP; Member and Managing Director of WP LLC
Jonathan S. Leff	Partner of WP; Member and Managing Director of WP LLC
Philip Mintz	Partner of WP; Member and Managing Director of WP LLC
James Neary	Partner of WP; Member and Managing Director of WP LLC
Bilge Ogut	Partner of WP; Member and Managing Director of WP LLC
Dalip Pathak	Partner of WP; Member and Managing Director of WP LLC
Michael F. Profenius	Partner of WP; Member and Managing Director of WP LLC
Justin Sadrian	Partner of WP; Member and Managing Director of WP LLC
Henry B. Schacht	Partner of WP; Member and Senior Advisor of WP LLC
Steven G. Schneider	Partner of WP; Member and Managing Director of WP LLC
Patrick Severson	Partner of WP; Member and Managing Director of WP LLC
John Shearburn	Partner of WP; Member and Managing Director of WP LLC
Barry Taylor	Partner of WP; Member and Managing Director of WP LLC
Christopher H. Turner	Partner of WP; Member and Managing Director of WP LLC
John L. Vogelstein	Partner of WP; Member and Senior Advisor of WP LLC
Elizabeth H. Weatherman	Partner of WP; Member and Managing Director of WP LLC
Rosanne Zimmerman	Partner of WP; Member and Managing Director of WP LLC
Pincus & Company LLC*
WP & Co. Partners,

L.P.**

Warburg Pincus Principal Partnership,  L.P.***

Warburg Pincus Real Estate Principal Partnership, L.P.***

Warburg Pincus 2006 Limited Partnership***

Warburg Pincus 2007 Limited Partnership***

*New York limited liability company; primary activity is ownership interest in WP and WP LLC

**New York limited partnership; primary activity is ownership interest in WP

***Delaware limited partnership; primary activity is ownership interest in WP

MEMBERS OF WP LLC

NAME	PRESENT PRINCIPAL OCCUPATION IN ADDITION TO POSITION WITH WP LLC, AND POSITIONS WITH THE REPORTING ENTITIES
Joel Ackerman	Member and Managing Director of WP LLC; Partner of WP
Scott A. Arenare	Member and Managing Director of WP LLC; Partner of WP
Pedro Aznar (1)	Member and Managing Director of WP LLC
David Barr	Member and Managing Director of WP LLC; Partner of WP
Sean D. Carney	Member and Managing Director of WP LLC; Partner of WP
Julian Cheng (2)	Member and Managing Director of WP LLC
Stephen John Coates (3)	Member and Managing Director of WP LLC
Mark Colodny	Member and Managing Director of WP LLC; Partner of WP
David A. Coulter	Member and Managing Director of WP LLC; Partner of WP
Timothy J. Curt	Member and Managing Director of WP LLC; Partner of WP
W. Bowman Cutter	Member and Managing Director of WP LLC; Partner of WP
Cary J. Davis	Member and Managing Director of WP LLC; Partner of WP
Rajiv Ghatalia (2)	Member and Managing Director of WP LLC
Steven Glenn	Member and Managing Director of WP LLC; Partner of WP
Michael Graff	Member and Managing Director of WP LLC; Partner of WP
Patrick T. Hackett	Member and Managing Director of WP LLC; Partner of WP
E. Davisson Hardman	Member and Managing Director of WP LLC; Partner of WP
Jeffrey A. Harris	Member and Managing Director of WP LLC; Partner of WP
Stewart J. Hen	Member and Managing Director of WP LLC; Partner of WP
William H. Janeway	Member and Senior Advisor of WP LLC; Partner of WP
Chansoo Joung	Member and Managing Director of WP LLC; Partner of WP
Peter R. Kagan	Member and Managing Director of WP LLC; Partner of WP
Charles R. Kaye	Managing Member and Co-President of WP LLC; Managing General Partner of WP
Rajesh Khanna (4)	Member and Managing Director of WP LLC
Henry Kressel	Member and Managing Director of WP LLC; Partner of WP
David Krieger	Member and Managing Director of WP LLC; Partner of WP
Kevin Kruse	Member and Managing Director of WP LLC; Partner of WP
Joseph P. Landy	Managing Member and Co-President of WP LLC; Managing General Partner of WP
Kewsong Lee	Member and Managing Director of WP LLC; Partner of WP
Jonathan S. Leff	Member and Managing Director of WP LLC; Partner of WP
David Li (2)	Member and Managing Director of WP LLC
Niten Malhan (4)	Member and Managing Director of WP LLC
Philip Mintz	Member and Managing Director of WP LLC; Partner of WP
Luca Molinari (5)	Member and Managing Director of WP LLC
James Neary	Member and Managing Director of WP LLC; Partner of WP
Bilge Ogut	Member and Managing Director of WP LLC; Partner of WP
Dalip Pathak	Member and Managing Director of WP LLC; Partner of WP
Michael F. Profenius	Member and Managing Director of WP LLC; Partner of WP
Leo Puri (4)	Member and Managing Director of WP LLC
Justin Sadrian	Member and Managing Director of WP LLC; Partner of WP
Henry B. Schacht	Member and Senior Advisor of WP LLC; Partner of WP
Steven G. Schneider	Member and Managing Director of WP LLC; Partner of WP
Joseph C. Schull (6)	Member and Managing Director of WP LLC
Patrick Severson	Member and Managing Director of WP LLC; Partner of WP
John Shearburn	Member and Managing Director of WP LLC; Partner of WP
Chang Q. Sun (2)	Member and Managing Director of WP LLC
Barry Taylor	Member and Managing Director of WP LLC; Partner of WP
Christopher H. Turner	Member and Managing Director of WP LLC; Partner of WP
Simon Turton (3)	Member and Managing Director of WP LLC
John L. Vogelstein	Member and Senior Advisor of WP LLC; Partner of WP

Elizabeth H. Weatherman	Member and Managing Director of WP LLC; Partner of WP
Peter Wilson (3)	Member and Managing Director of WP LLC
Jeremy S. Young (3)	Member and Managing Director of WP LLC
Rosanne Zimmerman	Member and Managing Director of WP LLC; Partner of WP
Pincus & Company LLC*

(1)Citizen of Germany

(2)Citizen of Hong Kong

(3)Citizen of United Kingdom

(4)Citizen of India

(5)Citizen of Italy

(6)Citizen of Canada

*  New York limited liability company; primary activity is ownership interest in WP and WP LLC

As of July 1, 2008

EX-2

Exhibit 2

Execution Version

SHARE PURCHASE AGREEMENT

SHARE PURCHASE AGREEMENT (the “Agreement”), dated as of June 1, 2008, by and among the parties listed in Schedule 1 (the “Selling Shareholders” and each individually a “Selling Shareholder”) and Warburg Pincus Private Equity X, L.P., a Delaware limited partnership, and Warburg Pincus X Partners, L.P., a Delaware limited partnership (the “Buyers” and each individually a “Buyer”).

WHEREAS:

The Buyers wish to purchase, and the Selling Shareholders desire to sell, upon the terms and conditions stated in this Agreement, a number of ordinary shares of WuXi PharmaTech (Cayman) Inc., a Cayman Islands company (the “Company”), par value U.S.$0.02 per ordinary share, equal to $63,000,000 divided by the higher of the Per Share Cash Purchase Price and the HSR Per Share Statutory Value (each as defined below) (the “Shares”).

NOW THEREFORE, the parties hereto hereby agree as follows:

1.PURCHASE AND SALE OF ORDINARY SHARES.

a.Purchase of Ordinary Shares.  Subject to the satisfaction (or waiver) of the conditions set forth in Sections 5 and 6 below and the provisions of Sections 1(b) and (c), the Selling Shareholders shall sell to the Buyers, and the Buyers agree to purchase from the Selling Shareholders, a number of shares equal to $63,000,000 divided by the higher of the Per Share Cash Purchase Price and the HSR Per Share Statutory Value and in the proportions as will be set forth opposite each Selling Shareholder’s name on the Schedule of Selling Shareholders attached as Schedule 1 (rounded to the nearest Share) which shall be agreed by the parties immediately following the completion of the calculations provided for in this Section 1(a) prior to Closing.  The purchase price per share (the “Per Share Cash Purchase Price”) of the Shares at the Closing (as defined below) shall be determined as follows: (i) if 95.0% of the Weighted Average Price (as defined below) (the “Net WAP”) is at least US$2.1250 but not more than US$2.5000 per Share, the Per Share Cash Purchase Price shall be US$2.5000 per Share, (ii) if the Net WAP is at least US$2.5010 but not more than US$2.8750, the Per Share Cash Purchase Price shall be the Net WAP per Share, (iii) if the Net WAP is at least US$2.8760 but not more than US$3.2500, the Per Share Cash Purchase Price shall be US$2.8750 per Share.  If the Net WAP is below US$2.1250 or above US$3.2500, then the Per Share Cash Purchase Price shall be mutually determined by the Buyers and the Selling Shareholders through good faith negotiations; provided, that in the event the parties hereto are unable to mutually agree on the Per Share Cash Purchase Price within five (5) Trading Days of the Closing Date originally proposed by the Buyers pursuant to Section 1(c), this Agreement may be terminated by either party in accordance with Section 9(k).  The “HSR Per Share Statutory Value” is the lowest daily closing bid price on the New York Stock Exchange for the Company’s American Depositary Shares (“ADSs”) divided by eight (8) within the forty-five (45) or fewer calendar days from the Closing Date (as defined below), but in no event to a date prior to May 30, 2008 (as initially determined on the close of trading on the second Trading Day prior to the Closing Date).  The “Weighted Average Price” for each Share means the average of the dollar-volume weighted average per ADS (divided by eight (8)) on the New York Stock Exchange during the period beginning at 9:30:01

am, New York Time (or such other time as the New York Stock Exchange publicly announces is the official open of trading), as reported by Bloomberg through its “Volume at Price” functions, for the following ten (10) Trading Days: (i) the five (5) consecutive Trading Day  period ending on the close of trading on the New York Stock Exchange on the fifth Trading Day after the date of this Agreement and (ii) the five (5) consecutive Trading Day period ending on the close of trading on the second Trading Day prior to the Closing Date  (as defined below).  Such determinations shall be appropriately adjusted for any stock dividend, stock split, stock combination, reclassification, ADS-to-ordinary share ratio change or similar transaction during the applicable calculation period.  “Trading Day” means each day on which the New York Stock Exchange is open for trading.  For the avoidance of doubt, if on the Closing Date the aggregate value of the Shares to be sold on the Closing Date based on the HSR Per Share Statutory Value (as re-determined on the Closing Date) exceeds $63,000,000, then the number of Shares to be sold on the Closing Date shall be proportionally reduced among the Selling Shareholders such that the aggregate HSR Per Share Statutory Value equals $63,000,000 and the parties agree to take such steps necessary to effect such reduction.

b.Addition of UOB Venture Technology as Selling Shareholder.  UOB Venture Technology Investments Ltd. (“UOB Venture Technology”) may be added as a Selling Shareholder under this Agreement upon execution of a Joinder Agreement in the form of Exhibit A and the Assignment Agreement in the form of Exhibit C and the Selling Shareholders shall deliver an amended Schedule 1 hereto.

c.Additional Officer and Employee Selling Shareholders.  Officers and employees of the Company may be added as additional Selling Shareholders under this Agreement, provided that only such Shares that are subject to registration rights pursuant to that certain registration rights agreement dated as of June 4, 2007 by and among the Company, the Selling Shareholders and certain other shareholders of the Company (the “Registration Rights Agreement”) are eligible to be sold pursuant to this Agreement, in respect of a number of Shares equal to up to $6,300,000 divided by the higher of the Per Share Cash Purchase Price and the HSR Per Share Statutory Value (the “Additional Share Value”).  No officers or employees shall be permitted to sell Shares hereunder unless they execute and deliver to the Buyers a Joinder Agreement in the form of Exhibit A and the Assignment Agreement in the form of Exhibit C.  In the event additional Shares are included pursuant to this Section 1(c), (i) the value of Shares to be sold by the Selling Shareholders as of the date of this Agreement and UOB Venture Technology (if added as a party hereto as contemplated by Section 1(b) above) shall be correspondingly reduced by the amount to be sold by the additional officer and employee Selling Shareholders and (ii) the amount of Shares totaling $6,300,000 divided by the Additional Share Value by all officer and employee Selling Shareholders shall be allocated proportionally based on the aggregate of all amounts to be sold by the Selling Shareholders (including the additional Selling Shareholders) and the parties shall agree to an amended Schedule 1 hereto.  For the avoidance of doubt, the total consideration for all Shares to be acquired under this Agreement shall not exceed $63,000,000 (as appropriately determined).

d.Closing Date.  The closing of the sale and purchase of the Shares as contemplated in this Agreement (the “Closing”) shall occur on the date and at the time specified in a written notice (the “Closing Notice”) provided by the Buyers to the Selling Shareholders, which date shall be two (2) Trading Days following delivery of such notice to the Selling

2

Shareholders (the “Closing Date”).  If the Net WAP is below US$2.1250 or above US$3.2500 and the Buyers and Selling Shareholders mutually agree on the Per Share Cash Purchase Price as contemplated in Section 1(a), the Buyers shall deliver to the Selling Shareholders a second Closing Notice promptly following such agreement specifying a new closing date and time, which shall be two (2) Trading Days following delivery of such second Closing Notice to the Selling Shareholders.  If given, any Closing Notice shall include an affirmative statement by the Buyers confirming that its due diligence with respect to the Company has been satisfactorily completed and the closing condition contained in Section 6(b) has been fulfilled.  The Closing shall occur at the offices of Morrison & Foerster, 41^st Floor, Edinburgh Tower, The Landmark, 15 Queen’s Road Central, Hong Kong, or at such other place as the Selling Shareholders and the Buyers may collectively designate in writing.

e.Form of Payment.  On the Closing Date, (i) the Buyers shall pay the aggregate Per Share Cash Purchase Prices to the Selling Shareholders for the Shares to be sold to the Buyers at the Closing, by wire transfer of immediately available funds in accordance with the Selling Shareholders’ written wire instructions (provided to Buyers not less than two (2) Trading Days prior to the Closing Date) and (ii) the Selling Shareholders shall deliver duly executed instruments of transfer and instructions to reflect Buyers’ ownership of the Shares on the Company’s share register (the “Closing Share Deliverables”) and promptly thereafter deliver the underlying certificate or certificates for the Shares.

2.BUYERS’ REPRESENTATIONS AND WARRANTIES.

Each of the Buyers represents and warrants to and agrees with the Selling Shareholders that:

a.Investment Purpose.  Such Buyer is acquiring the Shares for its own account and not with a view toward, or for resale in connection with, the sale or distribution thereof; provided, however, that by making the representations herein, such Buyer does not agree to hold the Shares for any minimum or other specific term, and reserves the right to dispose of the Shares at any time in accordance with or pursuant to a registration statement or an exemption under the United States Securities Act of 1933, as amended (the “1933 Act”).

b.Sophistication of Buyers.  By reason of its business or financial experience, such Buyer is capable of evaluating the risks and merits of an investment in the Company and of protecting its own interests in connection with this investment.

c.Accredited Investor Status.  Such Buyer is an “accredited investor” as that term is defined in Rule 501(a) of Regulation D as promulgated by the United States Securities and Exchange Commission (the “SEC”) under the 1933 Act.

d.Reliance on Exemptions.  Such Buyer understands that the Shares are being offered and sold to it in reliance on specific exemptions from the registration requirements of the United States federal and state securities laws and that the Selling Shareholders are relying in part upon the truth and accuracy of, and such Buyer’s compliance with, the representations, warranties, agreements, acknowledgments and understandings of such Buyer set forth herein in

3

order to determine the availability of such exemptions and the eligibility of such Buyer to acquire the Shares.

e.Transfer or Resale.  Such Buyer understands that the Shares have not been and are not being registered under the 1933 Act or any state securities laws, and may not be offered for sale, sold, assigned or transferred unless subsequently registered thereunder or sold, assigned or transferred pursuant to an exemption from registration under the 1933 Act.

f.Legends.  Such Buyer understands that the stock certificates representing the Shares except as set forth below, may bear a restrictive legend in substantially the following form (and a stop-transfer order may be placed against transfer of such stock certificates):

THE SECURITIES REPRESENTED BY THIS CERTIFICATE HAVE NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED.  THE SECURITIES MAY NOT BE OFFERED FOR SALE, SOLD, TRANSFERRED OR ASSIGNED (I) IN THE ABSENCE OF (A) AN EFFECTIVE REGISTRATION STATEMENT FOR THE SHARES UNDER THE SECURITIES ACT OF 1933, AS AMENDED OR (B) AN OPINION OF COUNSEL, IN A GENERALLY ACCEPTABLE FORM, THAT REGISTRATION IS NOT REQUIRED UNDER SAID ACT OR (II) UNLESS SOLD PURSUANT TO RULE 144 UNDER SAID ACT.

The legend set forth above shall be removed in respect of the Shares and the Company’s transfer agent shall issue a stock certificate without such legend to the holder thereof, unless otherwise required by state securities laws, if (i) such Shares are registered for resale under the 1933 Act and such shares have been sold in compliance with applicable prospectus delivery requirements, (ii) such holder provides the Company with an opinion of counsel, in a generally acceptable form, to the effect that a public sale, assignment or transfer of the Shares may be made without registration under the 1933 Act, or (iii) such holder provides the Company with reasonable assurance that the Shares have been sold, assigned or transferred pursuant to Rule 144.

g.Authorization; Enforcement; Validity.  This Agreement has been duly and validly authorized, executed and delivered on behalf of such Buyer, and is a valid and binding obligation of the Buyer enforceable against the Buyer in accordance with the respective terms herein, subject as to enforceability to applicable bankruptcy, insolvency, reorganization, moratorium, liquidation and other similar laws relating to, or affecting generally, the enforcement of applicable creditors’ rights and remedies.

3.REPRESENTATIONS AND WARRANTIES OF THE SELLING SHAREHOLDERS.

Each of the Selling Shareholders, represents and warrants to and agrees with the Buyers that:

a.This Agreement has been duly and validly authorized, executed and delivered on behalf of such Selling Shareholder, and is a valid and binding obligation of the Selling Shareholder enforceable against the Selling Shareholder in accordance with the

4

respective terms herein, subject as to enforceability to applicable bankruptcy, insolvency, reorganization, moratorium, liquidation and other similar laws relating to, or affecting generally, the enforcement of applicable creditors’ rights and remedies.

b.None of the execution and delivery by such Selling Shareholder of, and the performance by, such Selling Shareholder of its obligations under this Agreement will contravene any provision of applicable law, or the certificate of incorporation or by-laws or other organizational documents of such Selling Shareholder, or any agreement or other instrument binding upon such Selling Shareholder or any judgment, order or decree of any governmental body, agency or court having jurisdiction over such Selling Shareholder.

c.Such Selling Shareholder has, and on the Closing Date will have, valid title to the Shares to be sold by such Selling Shareholder free and clear of all security interests, claims, liens, equities or other encumbrances and the legal right and power, and all authorization and approval required by law, to enter into this Agreement and to sell, transfer and deliver the Shares to be sold by such Selling Shareholder.

d.Delivery of the Shares to be sold by such Selling Shareholder, the recording of the ownership of such Shares on the Company’s shareholder register and payment therefor pursuant to this Agreement will pass valid title to such Shares, free and clear of all security interests, claims, liens, equities or other encumbrances.

e.Such Selling Shareholder, or any person acting on behalf of such Selling Shareholder, has not directed any selling efforts in the United States with respect to the Shares.

f.No filing with, or consent, approval, authorization, order, registration, qualification or decree of, any court or governmental authority or agency, domestic or foreign, is necessary or required for the performance by such Selling Shareholder of its obligations hereunder or in connection with the sale and delivery of the Shares hereunder or the consummation of the transactions contemplated by this Agreement, except such as may have previously been made or obtained.

4.COVENANTS.

a.General.  Each party will use their commercially reasonable efforts to take all actions and to do all things necessary, proper or advisable to consummate and make effective the transactions contemplated by this Agreement (including satisfaction, but not waiver, of the closing conditions set forth in Section 5 and 6 as applicable).  In connection with the foregoing, the Buyers agree to (i) promptly commence their due diligence investigation of the Company, (ii) use commercially reasonable efforts to expeditiously pursue and conclude such investigation prior to June 30, 2008; and (iii) deliver the Closing Notice (as contemplated in Section 1(c)) promptly upon satisfactory completion of such diligence investigation.

b.Access and Investigation.  Between the date of this Agreement and the Closing Date, the Selling Shareholders shall use their commercially reasonable efforts to seek to cause the Company to cooperate with the Buyers and their advisors, agents and representatives with respect to the Buyers’ due diligence investigation of the Company and its business.  The

5

Selling Shareholders shall use their commercially reasonable efforts to seek to cause the Company to provide (on terms and at such time and in such manner and scope as is acceptable to the Company in its sole discretion) access to books, records, contracts and other information and data pertaining to the Company (if any) and its business, including arranging interviews with management, suppliers and customers of the Company.  The parties hereto acknowledge that the due diligence shall include legal, financial, business and technical aspects of the Company to assess the Buyers’ investment return profile, with a particular focus on assessing, without limitation, (i) the Company’s current and future service capabilities and customer needs and (ii) the Company’s technical, organizational and operational capabilities.   The Selling Shareholders acknowledge that the Buyers have not yet completed their legal, financial, business and technical due diligence review of the Company and that they may determine, in their sole and absolute discretion, that the purchase of the Shares contemplated hereby does not meet their investment objectives, for any reason or any combination of reasons.

c.UOB Schedule 1 Allocation.  The UOB entities party hereto (including UOB Technology Venture if added as a party hereto as contemplated by Section 1(b)) shall be jointly responsible for the sale of $63,000,000 of Shares under this Agreement (as appropriately determined) less any Shares to be sold by any Company officer and employee added as a party hereto as contemplated by Section 1(c).   Such UOB entities shall deliver to the Buyers (at least five (5) Trading Days prior to Closing) a modified Schedule 1 setting forth the allocation of Shares to be sold by them prior to the Closing Date, at which time such UOB entity shall only be responsible for its allocable share of the Shares to be sold by such UOB entity as set forth on Schedule 1 indicating its Share allocation.

d.Expenses.  The Selling Shareholders shall be responsible for the payment of any placement agent’s fees, underwriters’ fees or broker’s commissions relating to or arising out of the transactions contemplated hereby (other than any fees that the Buyers may have agreed to pay, which the Buyers represent there are none).  Except as otherwise set forth in this Agreement, each party to this Agreement shall bear its own expenses in connection with the sale of the Shares to the Buyers.

e.Board Observer.  The Selling Shareholders will in good faith consult with and recommend to the Company that the Buyers be permitted to have board observer rights on terms and conditions to be agreed upon between the Buyers and the Company in connection with the consummation of the transactions contemplated by this Agreement.

5.CONDITIONS TO THE OBLIGATION OF EACH SELLING SHAREHOLDER TO SELL.

The obligation of each Selling Shareholder to sell the Shares that it has agreed to sell to the Buyers at the Closing is subject to the satisfaction, at or before the Closing Date, of each of the following conditions, provided that these conditions are for the sole benefit of the Selling Shareholders and (except as expressly provided below) may be waived by the Selling Shareholders at any time in their sole discretion by providing the Buyers with prior written notice thereof:

6

a.The Buyers shall have delivered to the Selling Shareholders the Per Share Cash Purchase Price for the Shares being purchased by the Buyers from the Selling Shareholders by wire transfer of immediately available funds pursuant to the written wire instructions provided by the Selling Shareholders.

b.The representations and warranties of the Buyers shall be true and correct in all material respects as of the date when made and as of the Closing Date as though made at that time, and the Buyers shall have performed, satisfied and complied in all material respects with the covenants, agreements and conditions required by this Agreement to be performed, satisfied or complied with by the Buyers at or prior to the Closing Date.

c.Each Buyer shall have executed and delivered to each Selling Shareholder a receipt acknowledging each Buyer’s receipt of the Closing Share Deliverables in respect of the Shares to be purchased from such Selling Shareholder, in the amount set forth opposite each Selling Shareholder’s name on the Schedule attached hereto.

d.Each Buyer shall have delivered to each Selling Shareholder and the Company a letter substantially in the form of Exhibit B (the “Letter Agreement”).  In connection with the Letter Agreement, the parties hereto agree that the Company is a third-party beneficiary of this condition and this condition may not be waived without the prior written Company’s consent.

6.CONDITIONS TO THE BUYERS’ OBLIGATION TO PURCHASE.

The obligation of the Buyers hereunder to purchase the Shares from the Selling Shareholders at the Closing is subject to the satisfaction, at or before the Closing Date, of each of the following conditions, provided that these conditions are for the Buyers’ sole benefit and may be waived by the Buyers at any time in its sole discretion by providing the Selling Shareholders with prior written notice thereof:

a.The representations and warranties of the Selling Shareholders shall be true and correct in all material respects as of the date when made and as of the Closing Date as though made at that time and the Selling Shareholders shall have in all material respects performed, satisfied and complied with the covenants, agreements and conditions required by this Agreement.

b.Each Buyer shall be satisfied, in its sole and absolute discretion, with the results of its legal, financial, business and technical due diligence performed with respect to the Company.

c.The Selling Shareholders shall have assigned their rights under the Registration Rights Agreement, pursuant to an assignment agreement in form, scope and substance reasonably satisfactory to Buyers and in substantially the form of Exhibit C attached hereto, and the Company shall have consented in writing to such assignment.

d.The Buyers shall have received the opinion of both Cayman Islands legal counsel and Singapore legal counsel dated as of the Closing Date, in customary form, scope and substance reasonably satisfactory to the Buyers and the Selling Shareholders, and such other

7

legal opinions with respect to any additional Selling Shareholders joining this Agreement in accordance with Section 1(c) as may be reasonably requested by the Buyers.

e.On the Closing Date, the Selling Shareholders shall have delivered the Closing Share Deliverables in respect of the Shares to be sold by them pursuant to this Agreement.

f.Each Selling Shareholder shall have executed and delivered to the Buyers a cross-receipt acknowledging each Selling Shareholder’s receipt of the full aggregate Per Share Cash Purchase Price for the Shares purchased from such Selling Shareholder by the Buyers at the Closing.

g.The Selling Shareholder shall have delivered wire transfer instructions to the Buyers.

7.CONFIDENTIAL INFORMATION.

Each of the Buyers and the Selling Shareholders acknowledge and agree that this Agreement and the transaction contemplated herein are confidential, and no disclosure of any information regarding the Selling Shareholders, the Buyers or the Buyers’ affiliates, including information regarding this Agreement, is permitted other than to employees and/or business, legal or financial advisors of the Selling Shareholders or the Buyers who are on a “need to know” basis.  None of the parties hereto shall make any public statements regarding the existence of this Agreement or the terms hereof, the transaction contemplated herein and the identity of the parties, except (i) as the parties hereto mutually agree in writing (including the language on any disclosure) or (ii) until such time as the parties agree, based on the advice of counsel, that a public announcement is required by law or regulation, in which case the parties hereto shall in good faith attempt to agree on the content of any public announcements or publicity statements with respect thereto.  Notwithstanding the foregoing, the Selling Shareholders acknowledge (i) that each party may advise the Company of and provide to the Company a copy of this Agreement and nothing contained in this Section 7 is intended to limit or restrict the Company’s disclosure obligations under the U.S. securities laws and (ii) that if the Buyers individually or collectively acquire beneficial ownership of more than 5% of the outstanding shares of the Company they will be required to file a Schedule 13D with the SEC (which Schedule will contain as an exhibit thereto a copy of this Agreement), and nothing contained in this Section 7 is intended to limit or restrict such ability to file such Schedule 13D or any amendments thereto.  The covenants set forth in this Section 7 will survive indefinitely.

8.NO SOLICITATION.

From and after the date hereof until July 4, 2008 or, if earlier, the termination of this Agreement in accordance with Section 9(k), the Selling Shareholders shall not, and shall cause their affiliates, advisors and representatives not to, directly or indirectly: (i) initiate, solicit or knowingly encourage the submission of any inquiries, proposals or offers or any other efforts or attempts that constitute, or may reasonably be expected to lead to, any Acquisition Proposal or engage in any discussions or negotiations with respect thereto or otherwise cooperate with or assist or participate in or facilitate any such inquiries, proposals, offers, discussions or

8

negotiations (provided that the public announcement of the transaction contemplated hereby and any other public announcement or communication made in accordance with this Agreement shall not constitute a breach of this Section 8), (ii) approve or publicly propose to approve an Acquisition Proposal, (iii) enter into any purchase agreement, letter of intent, agreement in principle, share exchange agreement, option agreement or other similar agreement relating to an Acquisition Proposal or enter into any agreement or agreement in principle requiring the Selling Shareholders to abandon, terminate or fail to consummate the transactions contemplated hereby or breach their obligations hereunder, or (v) resolve, propose or agree to do any of the foregoing.  The Selling Shareholders shall immediately cease and cause to be terminated any solicitation, encouragement, discussion or negotiation with any third parties conducted theretofore by the Selling Shareholders or any of their affiliates, advisors or representatives with respect to any Acquisition Proposal.  “Acquisition Proposal” means any offer or proposal from any third party other than the Buyers or any of their affiliates concerning any direct or indirect acquisition of the $63,000,000 of Shares subject to this Agreement.

9.GOVERNING LAW; MISCELLANEOUS.

a.Governing Law; Jurisdiction; Jury Trial.  All questions concerning the construction, validity, enforcement and interpretation of this Agreement shall be governed by the internal laws of the State of New York, without giving effect to any choice of law or conflict of law provision or rule that would cause the application of the laws of any jurisdiction other than the State of New York.  Each party hereby irrevocably submits to the exclusive jurisdiction of the  courts sitting in the State of New York, for the adjudication of any dispute hereunder or in connection herewith or with any transaction contemplated hereby or discussed herein, and hereby irrevocably waives, and agrees not to assert in any suit, action or proceeding, any claim that it is not personally subject to the jurisdiction of any such court, that such suit, action or proceeding is brought in an inconvenient forum or that the venue of such suit, action or proceeding is improper.  Each party hereby irrevocably waives personal service of process and consents to process being served in any such suit, action or proceeding by mailing a copy thereof to such party at the address for such notices to it under this Agreement and agrees that such service shall constitute good and sufficient service of process and notice thereof.  Nothing contained herein shall be deemed to limit in any way any right to serve process in any manner permitted by law.  EACH PARTY HEREBY IRREVOCABLY WAIVES ANY RIGHT IT MAY HAVE, AND AGREES NOT TO REQUEST, A JURY TRIAL FOR THE ADJUDICATION OF ANY DISPUTE HEREUNDER OR IN CONNECTION HEREWITH OR ARISING OUT OF THIS AGREEMENT OR ANY TRANSACTION CONTEMPLATED HEREBY.

b.Counterparts.  This Agreement may be executed in two or more identical counterparts, all of which shall be considered one and the same agreement and shall become effective when counterparts have been signed by each party and delivered to the other party; provided that a facsimile signature shall be considered due execution and shall be binding upon the signatory thereto with the same force and effect as if the signature were an original, not a facsimile signature.

c.Headings.  The headings of this Agreement are for convenience of reference and shall not form part of, or affect the interpretation of, this Agreement.

9

d.             Severability.  If any provision of this Agreement shall be invalid or unenforceable in any jurisdiction, such invalidity or unenforceability shall not affect the validity or enforceability of the remainder of this Agreement in that jurisdiction or the validity or enforceability of any provision of this Agreement in any other jurisdiction.

e.             Entire Agreement; Amendments.  This Agreement supersedes all other prior oral or written agreements between the Buyers, the Selling Shareholders, their affiliates and persons acting on their behalf with respect to the matters discussed herein, and this Agreement contains the entire understanding of the parties with respect to the matters covered herein, and except as specifically set forth herein, neither the Selling Shareholders nor the Buyers makes any representation, warranty, covenant or undertaking with respect to such matters.  No provision of this Agreement may be amended other than by an instrument in writing signed by the Selling Shareholders and the Buyers; provided, further, that Section 5(d) hereof or the terms of the Letter Agreement may not be amended or waived without the written consent of the Company.

f.              Notices.  Any notices, consents, waivers or other communications required or permitted to be given under the terms of this Agreement must be in writing and will be deemed to have been delivered: (i) upon receipt, when delivered personally; (ii) upon receipt, when sent by facsimile (provided confirmation of transmission is mechanically or electronically generated and kept on file by the sending party); or (iii) three days after deposit with a internationally recognized overnight delivery service, in each case properly addressed to the party to receive the same.  The addresses and facsimile numbers for such communications shall be:

If to the Selling Shareholders:
The name and address set below such Selling Shareholder’s name on Schedule 1 attached hereto.
With a copy to:
	O’Melveny & Myers LLP
	Plaza 66, 37th Floor
	1266 Nanjing Road West Shanghai 100040, China
	Telephone: 86 21 230707000
	Facsimile: 86 21 2307-7300
	Attention: Kurt J. Berney
If to the Buyers:
	Warburg Pincus Private Equity X, L.P.
	466 Lexington Ave. New York, NY 10017
	Telephone:
	Facsimile: +1-212-878 9100
	Attention: Jonathan Leff

10

	Warburg Pincus X Partners, L.P.
	466 Lexington Ave. New York, NY 10017
	Telephone:
	Facsimile: +1-212-878 9100
	Attention: Jonathan Leff
With a copy to (for information purposes only):
	Morrison & Foerster
	41/F Edinburgh Tower
	The Landmark
	15 Queen’s Road Central
	Hong Kong
	Telephone: 852 2585-0888
	Facsimile: 852-2585-0800
	Attention: Paul W. Boltz, Jr.

Written confirmation of receipt (A) given by the recipient of such notice, consent, waiver or other communication, (B) mechanically or electronically generated by the sender’s facsimile machine containing the time, date, recipient facsimile number and an image of the first page of such transmission or (C) provided by an internationally recognized overnight delivery service shall be rebuttable evidence of personal service, receipt by facsimile or receipt from an internationally recognized overnight delivery service in accordance with clause (i), (ii) or (iii) above, respectively.

g.             Successors and Assigns.  This Agreement shall be binding upon and inure to the benefit of the parties and their respective successors and assigns.  The Buyers may assign some or all of their rights hereunder without the consent of the Selling Shareholders, provided, however, that any such assignment shall not release the Buyers from its obligations hereunder unless such obligations are assumed by such assignee and the Selling Shareholders have consented to such assignment and assumption, which consent shall not be unreasonably withheld.

h.             No Third Party Beneficiaries.  This Agreement is intended for the benefit of the parties hereto and their respective permitted successors and assigns and, except as provided in Section 5(d) hereof, is not for the benefit of, nor may any provision hereof be enforced by, any other person.

i.              Survival of Representations and Warranties.  All representations and warranties made by the Selling Shareholders and the Buyers in this Agreement or certificate or agreement delivered in connection with this Agreement shall survive the execution of this Agreement, the delivery to the Buyers of the Shares being purchased and the payment therefor for a period of one (1) year from the Closing Date.

11

j.Further Assurances.  Each party shall do and perform, or cause to be done and performed, all such further acts and things, and shall execute and deliver all such other agreements, certificates, instruments and documents, as the other party may reasonably request in order to carry out the intent and accomplish the purposes of this Agreement and the consummation of the transactions contemplated hereby.

k.Termination.  This Agreement may be terminated, and the transaction contemplated hereby may be abandoned, in the following circumstances:

(i)            By mutual written consent of the Buyers and the Selling Shareholders;

(ii)           By either Buyer or any Selling Shareholder, if a Buyer provides written notice to the Selling Shareholders to the effect that it is not satisfied, in its sole and absolute discretion, with the results of the legal, financial, business and technical due diligence review of the Company;

(iii)          By either the Buyers or the Selling Shareholders, upon written notice to the other party, in the event the Net WAP is below US$2.1250 or above US$3.2500 and the parties hereto are unable to mutually agree on the Per Share Cash Purchase Price in accordance with Section 1(a) above;

(iv)          By either the Buyers or the Selling Shareholders, if a Closing Notice shall not have been delivered on or before June 30, 2008; or

(v)           By either the Buyers or the Selling Shareholders, if Closing does not occur within two (2) Trading Days following delivery of the Closing Notice (or second Closing Notice, if the parties are required to mutually agree on the Per Share Cash Purchase Price in accordance with Section 1(a)).

Notwithstanding the foregoing, the right to terminate this Agreement pursuant to Sections 9(k)(iv) and (v) shall not be available to any party whose breach of this Agreement has been the cause or resulted in the failure of the Closing Notice to have been delivered on or before June 30, 2008.

l.No Strict Construction.  The language used in this Agreement will be deemed to be the language chosen by the parties to express their mutual intent, and no rules of strict construction will be applied against any party.

m.Remedies.  Each Buyer and each Selling Shareholder shall have all rights and remedies set forth herein and all of the rights which such parties have under any law.  Any party having any rights under any provision of this Agreement shall be entitled to enforce such rights specifically (without posting a bond or other security), to recover damages by reason of any breach of any provision of this Agreement and to exercise all other rights granted by law.

* * * * * *

12

IN WITNESS WHEREOF, the Buyers and the Selling Shareholders have caused this Share Purchase Agreement to be duly executed as of the date first written above.

SELLING SHAREHOLDER:		BUYER:
UOB Hermes Asia Technology Fund		Warburg Pincus Private Equity X, L.P.
By: UOB Venture Management PTE. Ltd.,		By: Warburg Pincus X, L.P., its general
its investment advisor		partner
		By: Warburg Pincus X LLC, its general
		partner
By:		By: Warburg Pincus Partners LLC, its
	Name:	managing member
	Title:	By: Warburg Pincus & Co., its managing
		member
		By:
		Name:
		Title:
SELLING SHAREHOLDER:		BUYER:
UOB JAIC Venture Bio Investments Limited		Warburg Pincus X Partners, L.P.
By: UOB Bioventures Management Pte Ltd,		By: Warburg Pincus X, L.P., its general
its investment manager		partner
		By: Warburg Pincus X LLC, its general
		partner
		By: Warburg Pincus Partners LLC, its
		managing member
		By: Warburg Pincus & Co., its managing
		member
By:		By:
	Name:	Name:
	Title:	Title:

13

Execution Version

Schedule 1

	Percentage of Shares / Buyer
Name of Selling Shareholder	Warburg Pincus Private Equity X, L.P. (which shall purchase 96.9% of all Shares to be sold)	Warburg Pincus X Partners, L.P. (which shall purchase 3.1% of all Shares to be sold)
UOB Hermes Asia Technology Fundc/o 80 Raffles Place #30-20 UOB Plaza 2, Singapore 048624Attention: Jean Thoh
UOB JAIC Venture Bio Investments Limited c/o 80 Raffles Place #30-20 UOB Plaza 2, Singapore 048624Attention: Jean Thoh
Total:$63,000,000 in Shares (as appropriately determined).See Section 4(c) for obligation to deliver allocation among UOB entities.

1

Exhibit A

JOINDER AGREEMENT

THIS JOINDER AGREEMENT, dated as of June     , 2008 (this “Agreement”), is by and among Warburg Pincus Private Equity X, L.P., a Delaware limited partnership, Warburg Pincus X Partners, L.P., a Delaware limited partnership (the “Buyers” and each individually a “Buyer”), UOB Hermes Asia Technology Fund, a Cayman Islands exempted company and UOB JAIC Venture Bio Investments Limited, a Singaporean limited liability company (together, the “Initial Sellers”) and each of the management shareholders of WuXi PharmaTech (Cayman) Inc. (the “Company”) listed in Schedule 1 hereto (the “Other Shareholders” and, collectively with the Buyers and the Initial Sellers, the “Parties”).  Capitalized terms used in this Agreement but not defined herein have the meanings assigned to them in the Share Purchase Agreement, dated as of June 1, 2008 (as the same may be amended or supplemented from time to time, the “Purchase Agreement”), by and among the Buyers and the Initial Sellers.

RECITALS

WHEREAS, the Buyers and the Initial Sellers have entered into the Purchase Agreement pursuant to which, among other things, the Buyers shall purchase from the Initial Sellers certain ordinary shares, par value US$0.02 per share, of the Company.

WHEREAS, Section 1(b) and (c) of the Purchase Agreement, respectively, provides that (i) UOB Venture Technology Investments Ltd., a Singaporean limited liability company, and (ii) officers and employees of the Company, may be added as additional Selling Shareholders under the Purchase Agreement upon execution of this Agreement.

WHEREAS, the Other Shareholders desire to execute this Agreement so that each such Other Shareholder will be deemed to be added as a party to the Purchase Agreement as a Selling Shareholder, and from and after the execution of this Agreement will be subject to all of the obligations hereunder and thereunder, and entitled to all of the benefits hereunder and thereunder, as a Selling Shareholder.

AGREEMENT

In consideration of the foregoing and the mutual covenants and agreements herein contained, and intending to be legally bound hereby, the Parties agree as follows:

ARTICLE I CONSENT

Section 1.1          Joinder.

(a)           Each Other Shareholder hereby acknowledges that it has received and reviewed a copy of the Purchase Agreement and all other documents it deems fit to enter into this Agreement and acknowledges and agrees to: (i) join and become a party to the Purchase Agreement as indicated by his or her signature below; (ii) be bound by all covenants, terms, conditions, agreements, representations, warranties and acknowledgments attributable to a

Selling Shareholder under the Purchase Agreement, and (iii) perform all obligations and duties required of a Selling Shareholder pursuant to the Purchase Agreement as though such Other Shareholder was an original party thereto.

(b)           Each Selling Shareholder hereby represents and warrants that he or she has all the requisite capacity and authority to execute, deliver and perform his or her obligations under this Agreement and that when this Agreement is executed and delivered, it will constitute a valid and legally binding agreement enforceable against such Selling Shareholder in accordance with its terms, subject as to enforceability to applicable bankruptcy, insolvency, reorganization, moratorium, liquidation and other similar laws relating to, or affecting generally, the enforcement of applicable creditors’ rights and remedies.

ARTICLE II TERMINATION

Section 2.1          Termination.  This Agreement may be terminated at any time by consent of the Parties hereto and will terminate automatically if the Purchase Agreement has been terminated in accordance with the terms thereof.

Section 2.2          Effect of Termination.  In the event of termination of this Agreement, this Agreement shall forthwith become null and void and there shall be no continuing obligation or liability on the part of any party, except that nothing herein shall relieve any Other Shareholder from liability for any breach of this Agreement arising prior to or simultaneously with such termination and except as set forth in the Purchase Agreement.

ARTICLE III MISCELLANEOUS

Section 3.1          Amendments; Waivers.  This Agreement may be amended or modified only by a written instrument executed by the Parties.  Any of the terms and conditions of this Agreement may be waived, but only by a written instrument executed by the Party granting such waiver. Any such waiver shall constitute a waiver only with respect to the specific matter described in such instrument and shall in no way impair the rights of the Party granting such waiver in any other respect or at any other time.

Section 3.2          Notices.

(a)           All notices, requests, consents and other communications hereunder to any Party shall be deemed to be sufficient if contained in a written instrument delivered in person or by telecopy (or similar electronic means with a copy by internationally-recognized overnight courier) or sent by internationally-recognized overnight courier addressed to such Party at the address set forth below or at such other address as may hereafter be designated in writing by such Party to the other Parties.

If to the Other Shareholders:

The name and address set below such Selling Shareholder’s name on Schedule 1 attached hereto.

With a copy to:

	O’Melveny & Myers LLP
	Plaza 66, 37th Floor
	1266 Nanjing Road West Shanghai 100040, China
	Telephone: 86 21 230707000
	Facsimile: 86 21 2307-7300
	Attention: Kurt J. Berney
If to the Initial Sellers:
The names and addresses set forth in the Purchase Agreement.
If to the Buyers:
The names and addresses set forth in the Purchase Agreement.

(b)           All such notices, requests, consents and other communications shall be deemed to have been delivered and received: (i) in the case of personal delivery or delivery by facsimile, on the date of such delivery (and, if such date is not a Business Day, then on the next Business Day); and (ii) in the case of dispatch by internationally-recognized overnight courier, on the next Business Day following such dispatch.

Section 3.3          Entire Agreement.  This Agreement (including the Exhibits and Schedules hereto) and the Purchase Agreement (including the Exhibits and Schedules thereto) contain the entire agreement among the Parties with respect to the subject matter hereof and supersede all prior agreements and understandings, written or oral, with respect to such subject matter, and any term sheets or letters of intent provided by any Party.  The Parties hereto represent and warrant that there are no other agreements or understandings, written or oral, regarding any of the subject matter hereof other than as set forth herein and covenant not to enter into any such agreements or understandings after the date hereof, except pursuant to an amendment, modification or waiver of the provisions of this Agreement or the Purchase Agreement, as applicable.

Section 3.4          Governing Law; Jurisdiction; Jury Trial.  All questions concerning the construction, validity, enforcement and interpretation of this Agreement shall be governed by the internal laws of the State of New York, without giving effect to any choice of law or conflict of law provision or rule that would cause the application of the laws of any jurisdiction other than the State of New York.  Each party hereby irrevocably submits to the exclusive jurisdiction of the  courts sitting in the State of New York, for the adjudication of any dispute hereunder or in connection herewith or with any transaction contemplated hereby or discussed herein, and hereby irrevocably waives, and agrees not to assert in any suit, action or proceeding, any claim that it is not personally subject to the jurisdiction of any such court, that such suit, action or proceeding is brought in an inconvenient forum or that the venue of such suit, action or proceeding is improper.  Each party hereby irrevocably waives personal service of process and consents to process being served in any such suit, action or proceeding by mailing a copy thereof to such party at the address for such notices to it under this Agreement and agrees that

such service shall constitute good and sufficient service of process and notice thereof.  Nothing contained herein shall be deemed to limit in any way any right to serve process in any manner permitted by law.  EACH PARTY HEREBY IRREVOCABLY WAIVES ANY RIGHT IT MAY HAVE, AND AGREES NOT TO REQUEST, A JURY TRIAL FOR THE ADJUDICATION OF ANY DISPUTE HEREUNDER OR IN CONNECTION HEREWITH OR ARISING OUT OF THIS AGREEMENT OR ANY TRANSACTION CONTEMPLATED HEREBY.

Section 3.5          No Third Party Beneficiaries.  This Agreement is intended for the benefit of the Parties hereto and their respective permitted successors and assigns, and is not for the benefit of, nor may any provision hereof be enforced by, any other person.

Section 3.6          Counterparts.  This Agreement may be executed in two or more identical counterparts, all of which shall be considered one and the same agreement and shall become effective when counterparts have been signed by each party and delivered to the other party; provided that a facsimile signature shall be considered due execution and shall be binding upon the signatory thereto with the same force and effect as if the signature were an original, not a facsimile signature.

Section 3.7          Severability of Provisions.  If any provision of this Agreement shall be invalid or unenforceable in any jurisdiction, such invalidity or unenforceability shall not affect the validity or enforceability of the remainder of this Agreement in that jurisdiction or the validity or enforceability of any provision of this Agreement in any other jurisdiction.

Section 3.8          Assignments; Successors and Assigns.  This Agreement shall be binding upon and inure to the benefit of the Parties and their respective successors and assigns.  The Buyers may assign some or all of their rights hereunder without the consent of the Selling Shareholders, provided, however, that any such assignment shall not release the Buyers from its obligations hereunder unless such obligations are assumed by such assignee and the Selling Shareholders have consented to such assignment and assumption, which consent shall not be unreasonably withheld.

Section 3.9          Headings.  The headings of this Agreement are for convenience of reference and shall not form part of, or affect the interpretation of, this Agreement.

Section 3.10        Interpretation.  When a reference is made in this Agreement to a Section, Article or Exhibit such reference shall be to a Section, Article or Exhibit of this Agreement unless otherwise indicated.  The headings contained in this Agreement or in any Exhibit are for convenience of reference purposes only and shall not affect in any way the meaning or interpretation of this Agreement.  All words used in this Agreement will be construed to be of such gender or number as the circumstances require.  Any capitalized terms used in any Exhibit but not otherwise defined therein shall have the meaning as defined in this Agreement.  All Exhibits annexed hereto or referred to herein are hereby incorporated in and made a part of this Agreement as if set forth herein.  The word “including” and words of similar import when used in this Agreement will mean “including, without limitation”, unless otherwise specified.

Section 3.11        Facsimile Signature.  This Agreement may be executed by facsimile signature and a facsimile signature shall constitute an original for all purposes.

Section 3.12        No Presumption Against Drafting Party.  Each of the Buyers, the Initial Sellers and the Other Shareholders acknowledges that each Party to this Agreement has been represented by counsel in connection with this Agreement and the transactions contemplated by this Agreement.  Accordingly, any rule of law or any legal decision that would require interpretation of any claimed ambiguities in this Agreement against the drafting Party has no application and is expressly waived.

[The next page is the signature page]

IN WITNESS WHEREOF, the Parties have caused this Joinder Agreement to be executed as of the date first written above personally or by their respective officers thereunto duly authorized.

OTHER SHAREHOLDERS:	BUYER:
	Warburg Pincus Private Equity X, L.P.
	By: Warburg Pincus X, L.P., its general
Name:	partner
	By: Warburg Pincus X LLC, its general
	partner
	By: Warburg Pincus Partners LLC, its
	managing member
	By: Warburg Pincus & Co., its managing
	member
	By:
Name:	Name:
	Title:
	BUYER:
	Warburg Pincus X Partners, L.P.
	By: Warburg Pincus X, L.P., its general
Name:	partner
	By: Warburg Pincus X LLC, its general
	partner
	By: Warburg Pincus Partners LLC, its
	managing member
	By: Warburg Pincus & Co., its managing
	member

		By:
Name:		Name:
		Title:
INITIAL SELLERS:
UOB Hermes Asia Technology Fund
By: UOB Venture Management PTE. Ltd.,
its investment advisor
By:
	Name:
	Title:
UOB JAIC Venture Bio Investments Limited
By: UOB Bioventures Management Pte Ltd,
its investment manager
By:
	Name:
	Title:

Schedule 1

LIST OF OTHER SHAREHOLDERS

Name of Other Shareholder Address

Exhibit B

[closing date], 2008

WuXi PharmaTech (Cayman) Inc.

288 Fute Zhong Road

Waigaoqiao Free Trade Zone

Shanghai 200131

People’s Republic of China

UOB Hermes Asia Technology Fund

UOB JAIC Venture Bio Investments Limited

UOB Venture Technology Investments Ltd.

c/o 80 Raffles Place #30-20

UOB Plaza 2, Singapore 048624

Ladies and Gentlemen:

Reference is made to the Share Purchase Agreement (the “Agreement”), dated as of June 1, 2008, by and among the parties listed in Schedule 1 (the “Selling Shareholders” and each individually a “Selling Shareholder”) and Warburg Pincus Private Equity X, L.P., a Delaware limited partnership, and Warburg Pincus X Partners, L.P., a Delaware limited partnership (the “Buyers” and each individually a “Buyer”).

Each Buyer wishes to purchase, and each Selling Shareholder desires to sell, upon the terms and conditions stated in the Agreement, an agreed upon number of ordinary shares of WuXi PharmaTech (Cayman) Inc., a Cayman Islands company (the “Company”), par value U.S.$0.02 per ordinary share (the “Shares”).

As a condition to each Selling Shareholder’s agreement to sell and each Buyer’s agreement to purchase the Shares and the Company’s agreement to furnish certain information to the Buyers regarding the Company, its financial condition, results of operations, businesses, properties, assets, liabilities, management, projections, appraisals, plans, prospects and other information relating to the Company (the “Information”), each Selling Shareholder and each Buyer agrees to irrevocably release, discharge, waive and dismiss against the other and the Company any and all claims, rights, remedies, causes of action, suits, obligations, debts, demands, agreements, promises, liabilities, losses, costs, expenses, fees or damages of any kind, whether known or unknown, accrued or not accrued, foreseen or unforeseen or matured or not matured that they now or may hereafter have (including, but not limited to, any and all claims alleging violations of U.S. federal or state securities laws, fraud or deceit, breach of fiduciary duty, negligence or otherwise), if any, against the other or the Company or any of their respective officers, directors, members, shareholders, partners, agents or employees with respect to the Information or non-disclosure of the Information.

Each Buyer (and any other party on whose behalf such party is acting) further represents and warrants to the other party hereto:

1.  It has read and reviewed the publicly available information concerning the Company, including without limitation the information concerning the Company filed with the U.S. Securities and Exchange Commission, and has been advised by counsel regarding the material terms of the Shares and an investment therein.

 2.  It is (i) a “qualified institutional buyer” as defined in Rule 144A under the Securities Act of 1933, as amended (the “Securities Act”), (ii) an “institutional accredited investor” as defined under Rule 501(a)(1), (2), (3) or (7) under the Securities Act, or (ii) a “non-U.S. person”, as that term is defined in Rule 902 under the Securities Act.

3.  It (a) is a sophisticated purchaser with respect to Shares, (b) has adequate information concerning the Shares, (c) has adequate information concerning the business and financial condition of the Company and any affiliates of the Company, (d) has conducted, to the extent it deemed necessary, an independent investigation of such matters as, in its judgment, is necessary or advisable for it to make an informed investment decision with respect to the Shares and the Company, and (e) has not relied upon the Buyer or the Company for any investigation into, assessment of, or evaluation with respect to the Shares and the Company.

Each Buyer hereby further acknowledges that, other than as included in this letter agreement or the Agreement (in the case of the Selling Shareholders), neither the Company nor any Selling Shareholder is making nor has made any representations or warranties with respect to the Company or the transactions contemplated hereby.  Please indicate your acknowledgement and agreement to the foregoing by signing below where indicated.

[Signature page follows]

		BUYER:
		Warburg Pincus Private Equity X, L.P.
		By:	Warburg Pincus X, L.P., its general partner
		By:	Warburg Pincus X LLC, its general partner
		By:	Warburg Pincus Partners LLC, its managing
		member
		By:	Warburg Pincus & Co., its managing
		member
		By:
		Name:
		Title:
		BUYER:
		Warburg Pincus X Partners, L.P.
		By:	Warburg Pincus X, L.P., its general partner
		By:	Warburg Pincus X LLC, its general partner
		By:	Warburg Pincus Partners LLC, its managing
		member
		By:	Warburg Pincus & Co., its managing
		member
		By:
		Name:
		Title:
ACCEPTED AND AGREED TO:
SELLING SHAREHOLDER:
UOB Hermes Asia Technology Fund
By: UOB Venture Management PTE. Ltd., its investment advisor
By:
	Name:
	Title:

SELLING SHAREHOLDER:
UOB JAIC Venture Bio Investments Limited
By: UOB Bioventures Management Pte Ltd, its investment manager
By:
	Name:
	Title:
SELLING SHAREHOLDER:
UOB Venture Technology Investments Ltd.
By: UOB Venture Management Pte Ltd, its investment manager
By:
	Name:
	Title:
COMPANY:
WuXi PharmaTech (Cayman) Inc.
By:
	Name:
	Title:

Exhibit C

ASSIGNMENT AGREEMENT

THIS ASSIGNMENT AGREEMENT (this “Assignment”) is made and entered into as of [          ], 2008 by and among UOB Hermes Asia Technology Fund, a Cayman Islands exempted company, UOB JAIC Venture Bio Investments Limited, a Singaporean limited liability company, and UOB Venture Technology Investments Ltd., a Singaporean limited liability company (together, the “Assignors”), Warburg Pincus Private Equity X, L.P. a Delaware limited partnership, or a wholly owned subsidiary thereof and Warburg Pincus X Partners, L.P., a Delaware limited partnership, or a wholly owned subsidiary thereof (together, the “Assignees”) (collectively, the “Parties” and individually a “Party”).  All capitalized terms

not otherwise defined herein shall have the meanings given in the Registration Rights Agreement (as hereafter defined).

RECITALS

A.            In connection with the sale by Assignors of ordinary shares (the “Shares”), par value US$0.02 per share, of WuXi PharmaTech (Cayman) Inc. (the “Company”) to Assignees pursuant to that certain Share Purchase Agreement (the “Share Purchase Agreement”), dated June 1, 2008, by and among Assignees and Assignors, Assignors have agreed to transfer, convey and assign all rights associated with the Shares under that certain Registration Rights Agreement (the “Registration Rights Agreement”), dated June 4, 2007, by and among the Company, the Assignors and certain other shareholders of the Company party thereto, pursuant to the terms and conditions set forth in the Share Purchase Agreement.

B.            In connection with the sale of the Shares to Assignees and upon the terms and conditions of this Assignment, Assignors desire to assign and transfer all rights associated with the Shares under the Registration Rights Agreement and Assignees desire to accept and assume such rights.

AGREEMENT

NOW, THEREFORE, in consideration of the mutual promises contained herein and for other good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged, and intending to be legally bound hereby, the Parties agree as follows:

1.             Assignment.  Assignors hereby unconditionally and irrevocably assign, transfer, and convey to Assignees, all of their rights and obligations under the Registration Rights Agreement with respect to the Shares being sold pursuant to the Share Purchase Agreement (including, without limitation, Demand Registration, Incidental or “Piggy-Back Registration” and Form F-3 Registration rights) (the “Registration Rights”).

2.             Acceptance.  Assignees hereby accept the foregoing assignment, transfer and conveyance of the Registration Rights.

3.             Effectiveness.  Assignors and Assignees have agreed that this Assignment shall be effective immediately upon Closing (as defined in the Share Purchase Agreement).

4.             Representations and Warranties of Assignors.  Assignors hereby represent and warrant that (i) they are the legal and direct holders of the Registration Rights, (ii) they have not assigned or purported to assign any right with respect thereto to any person or entity, and (iii) no other person or entity has any right, title or interest in or to the Registration Rights.

5.             Representations and Warranties of the Parties.  Each of the Assignors, jointly and severally, and each of the Assignees, jointly and severally represent and warrant that (i) such Party has the full and requisite power and authority to execute and deliver this Assignment and to perform its obligations and consummate the transactions contemplated hereunder, (ii) this

Assignment has been duly and validly authorized, executed and delivered by such Party and this Assignment constitutes the legal, valid and binding obligation of such Party, enforceable against such Party in accordance with its terms, subject as to enforceability to applicable bankruptcy, insolvency, reorganization, moratorium, liquidation and other similar laws relating to, or affecting generally, the enforcement of applicable creditors’ rights and remedies, and (iii) neither the execution of this Assignment nor the exercise of the rights or performance of the obligations under this Assignment by such Party constitutes a breach of, or default under, any laws and regulations applicable to such Party, such Party’s organizational documents or any agreements to which such Party is a party which would materially affect the transactions contemplated by this Assignment.

6.             Successors.  The provisions of this Assignment shall be binding upon and inure to the benefit of Assignors and Assignees, their successors in interest and assigns.

7.             Governing Law.  All questions concerning the construction, validity, enforcement and interpretation of this Agreement shall be governed by the internal laws of the State of New York, without giving effect to any choice of law or conflict of law provision or rule that would cause the application of the laws of any jurisdiction other than the State of New York.

8.             Amendments; No Waiver.  No modifications of or any changes to this Assignment shall be effective unless made in writing and signed by each of the Parties.  No waiver of any provision of this Assignment by a Party shall constitute a waiver of any other provision(s) or of the same provisions on another occasion.

9.             Further Assurances.  Each of the Parties shall execute such documents and perform such further acts (including, without limitation, obtaining any consents, exemptions, authorizations, or other actions by, or giving any notices to, or making any filings with, any governmental authority or any other person or entity) as may be reasonably required or desirable to carry out or to perform the provisions of this Assignment.

10.           Counterparts.  This Assignment may be executed in counterparts, all of which shall be considered one and the same agreement and shall become effective when counterparts have been signed by each party and delivered to the other party; provided that a facsimile signature shall be considered due execution and shall be binding upon the signatory thereto with the same force and effect as if the signature were an original, not a facsimile signature.

IN WITNESS WHEREOF, this Assignment has been entered into on the date first above written.

ASSIGNORS:	ASSIGNEE:
UOB Hermes Asia Technology Fund	Warburg Pincus Private Equity X, L.P.
By: UOB Venture Management PTE. Ltd.,	By:	Warburg Pincus X, L.P., its general
its investment advisor	partner
	By:	Warburg Pincus X LLC, its general
	partner

		By:	Warburg Pincus Partners LLC, its
		managing member
		By:	Warburg Pincus & Co., its managing
		member
By:		By:
	Name:	Name:
	Title:	Title:
		ASSIGNEE:
UOB JAIC Venture Bio Investments Limited
		Warburg Pincus X Partners, L.P.
By: UOB Bioventures Management Pte Ltd, its investment manager
		By:	Warburg Pincus X, L.P., its general
		partner
		By:	Warburg Pincus X LLC, its general
		partner
		By:	Warburg Pincus Partners LLC, its
		managing member
		By:	Warburg Pincus & Co., its managing
		member
By:		By:
	Name:	Name:
	Title:	Title:
UOB Venture Technology Investments Ltd.
By: UOB Venture Management Pte Ltd, its investment manager
By:
	Name:
	Title:
THE COMPANY:
The Company hereby acknowledges and agrees to the foregoing assignment of the Registration Rights by Assignors to Assignees.
WuXi PharmaTech (Cayman) Inc., a Cayman Islands company
By:
	Name:
	Title:

EX-3

Exhibit 3

AMENDMENT NO. 1 TO THE SHARE PURCHASE AGREEMENT

AMENDMENT AGREEMENT (the “Amendment Agreement”), dated as of July 2, 2008, by and among Warburg Pincus Private Equity X, L.P., a Delaware limited partnership, and Warburg Pincus X Partners, L.P., a Delaware limited partnership (together, the “Buyers”), UOB Hermes Asia Technology Fund, a Cayman Islands exempted company, UOB JAIC Venture Bio Investments Limited, a Singaporean limited liability company, and UOB Venture Technology Investments Ltd., a Singaporean limited liability company, (together, the “Selling Shareholders”).

RECITALS:

WHEREAS, the Buyers and the Selling Shareholders are parties to that certain Share Purchase Agreement dated as of June 1, 2008 (the “Share Purchase Agreement”), with UOB Venture Technology Investments Ltd. being made a party thereto pursuant to that certain Joinder Agreement among the Buyers and the Selling Shareholders dated as of June 20, 2008; and

WHEREAS, in accordance with Section 9(e) of the Share Purchase Agreement, the Buyers and the Selling Shareholders desire to amend certain provisions of the Share Purchase Agreement as set forth below.

NOW THEREFORE, the parties hereto hereby agree as follows:

1.DEFINITIONS

a.Definitions in Amendment Agreement.  Unless otherwise defined herein, terms defined in the Share Purchase Agreement (as amended hereby) are used herein as therein defined.

2.AMENDMENTS TO THE SHARE PURCHASE AGREEMENT

a.Sections 1(a) and 1(d) of the Share Purchase Agreement are hereby amended in their entirety to read as follows:

b.Purchase of Ordinary Shares.  Subject to the satisfaction (or waiver) of the conditions set forth in Sections 5 and 6 below and the provisions of Sections 1(b) and (c), the Selling Shareholders shall sell to the Buyers, and the Buyers agree to purchase from the Selling Shareholders, a number of shares equal to $63,000,000 divided by the higher of the Per Share Cash Purchase Price and the HSR Per Share Statutory Value and in the proportions as will be set forth opposite each Selling Shareholder’s name on the Schedule of Selling Shareholders attached as Schedule 1 (rounded to the nearest Share) which shall be agreed by the parties immediately following the completion of the calculations provided for in this Section 1(a) prior to Closing.  The purchase price per share (the “Per Share Cash Purchase Price”) of the Shares at the Closing (as defined below) shall be $2.35.  The “HSR Per Share Statutory Value” is the lowest daily closing bid price on the New York Stock Exchange for the Company’s American Depositary Shares (“ADSs”) divided by eight (8) within the forty-five (45) or fewer calendar days from the Closing Date (as defined below), but in no event to a date prior to May 30, 2008 (as initially determined on the close of trading on the second Trading Day prior to the Closing

Date).  “Trading Day” means each day on which the New York Stock Exchange is open for trading.  For the avoidance of doubt, if on the Closing Date the aggregate value of the Shares to be sold on the Closing Date based on the HSR Per Share Statutory Value (as re-determined on the Closing Date) exceeds $63,000,000, then the number of Shares to be sold on the Closing Date shall be proportionally reduced among the Selling Shareholders such that the aggregate HSR Per Share Statutory Value equals $63,000,000 and the parties agree to take such steps necessary to effect such reduction.

c.Closing Date.  The closing of the sale and purchase of the Shares as contemplated in this Agreement (the “Closing”) shall occur on the date and at the time specified in a written notice (the “Closing Notice”) provided by the Buyers to the Selling Shareholders, which date shall be two (2) Trading Days following delivery of such notice to the Selling Shareholders (the “Closing Date”).  If given, any Closing Notice shall include an affirmative statement by the Buyers confirming that its due diligence with respect to the Company has been satisfactorily completed and the closing condition contained in Section 6(b) has been fulfilled.  The Closing shall occur at the offices of Morrison & Foerster, 41st Floor, Edinburgh Tower, The Landmark, 15 Queen’s Road Central, Hong Kong, or at such other place as the Selling Shareholders and the Buyers may collectively designate in writing.

d.Section 9(k)(iii) of the Share Purchase Agreement is hereby deleted in its entirety.

e.Section 9(k)(v) of the Share Purchase Agreement is hereby amended in its entirety to read as follows:

(i)By either the Buyers or the Selling Shareholders, if Closing does not occur within two (2) Trading Days following delivery of the Closing Notice.

3.GOVERNING LAW; MISCELLANEOUS.

a.No Other Changes. Except as otherwise expressly provided by this Amendment Agreement, all of the terms, conditions and provisions of the Share Purchase Agreement, and all rights and remedies of the Buyers and Selling Shareholders thereunder, shall remain unaltered.

b.Governing Law; Jurisdiction; Jury Trial.  All questions concerning the construction, validity, enforcement and interpretation of this Amendment Agreement shall be governed by the internal laws of the State of New York, without giving effect to any choice of law or conflict of law provision or rule that would cause the application of the laws of any jurisdiction other than the State of New York.  Each party hereby irrevocably submits to the exclusive jurisdiction of the  courts sitting in the State of New York, for the adjudication of any dispute hereunder or in connection herewith or with any transaction contemplated hereby or discussed herein, and hereby irrevocably waives, and agrees not to assert in any suit, action or proceeding, any claim that it is not personally subject to the jurisdiction of any such court, that such suit, action or proceeding is brought in an inconvenient forum or that the venue of such suit, action or proceeding is improper.  Each party hereby irrevocably waives personal service of

2

process and consents to process being served in any such suit, action or proceeding by mailing a copy thereof to such party at the address for such notices to it under this Amendment Agreement and agrees that such service shall constitute good and sufficient service of process and notice thereof.  Nothing contained herein shall be deemed to limit in any way any right to serve process in any manner permitted by law.  EACH PARTY HEREBY IRREVOCABLY WAIVES ANY RIGHT IT MAY HAVE, AND AGREES NOT TO REQUEST, A JURY TRIAL FOR THE ADJUDICATION OF ANY DISPUTE HEREUNDER OR IN CONNECTION HEREWITH OR ARISING OUT OF THIS AMENDMENT AGREEMENT OR ANY TRANSACTION CONTEMPLATED HEREBY.

c.Counterparts.  This Amendment Agreement may be executed in two or more identical counterparts, all of which shall be considered one and the same agreement and shall become effective when counterparts have been signed by each party and delivered to the other party; provided that a facsimile signature shall be considered due execution and shall be binding upon the signatory thereto with the same force and effect as if the signature were an original, not a facsimile signature.

[The remainder of this page intentionally left blank]

3

IN WITNESS WHEREOF, the Buyers and the Selling Shareholders have caused this Amendment Agreement to be duly executed as of the date first written above.

BUYER:

Warburg Pincus Private Equity X, L.P.

By: Warburg Pincus X, L.P., its general partner
By: Warburg Pincus X LLC, its general partner
By: Warburg Pincus Partners LLC, its managing
member
By: Warburg Pincus & Co., its managing member

By:

Name:

Title:

BUYER:

Warburg Pincus X Partners, L.P.

By: Warburg Pincus X, L.P., its general partner
By: Warburg Pincus X LLC, its general partner
By: Warburg Pincus Partners LLC, its managing
member
By: Warburg Pincus & Co., its managing member

By:

Name:

Title:

ACCEPTED AND AGREED TO:
SELLING SHAREHOLDER:
UOB Hermes Asia Technology Fund
By: UOB Venture Management Pte. Ltd., its investment advisor
By:
	Name:
	Title:

SELLING SHAREHOLDER:
UOB JAIC Venture Bio Investments Limited
By: UOB Bioventures Management Pte. Ltd., its investment manager
By:
	Name:
	Title:
SELLING SHAREHOLDER:
UOB Venture Technology Investments Ltd.
By: UOB Venture Management Pte. Ltd., its investment manager
By:
	Name:
	Title: